Conventionally, there has been proposed a method in which information on acceleration acting on a tire is acquired by an acceleration sensor attached to inside of the tire and, from the acquired acceleration information, a condition of a road surface on which the tire is running and uneven wear of the tire are estimated.
As the above-mentioned acceleration information, for example, an acceleration waveform in a tire circumferential direction, an acceleration waveform in a tire width direction or an acceleration waveform in a tire radial direction, which acts on a tread of the running tire, is used (see PTL 1, for example).